Tunable Functionalization of Saturated C-C and C-H Bonds of N,N'-Diarylpiperazines Enabled by tert-Butyl Nitrite (TBN) and NaNO2 Systems.

A tunable functionalization of saturated C-C and C-H bonds of N,N'-diarylpiperazine derivatives was realized by tert-butyl nitrite (TBN) and NaNO2 systems, respectively. When TBN was employed as the oxidant, C-C bond cleavage occurred smoothly, providing a series of formamides in good yields. In the presence of NaNO2, C-H oxidation was achieved, resulting in efficient synthesis of nitroalkenes. The mechanistic study shows that a mixed mechanism is involved in these reactions, in which a generated enamine might be the key intermediate.